Physiological effects of emphysema may include all of the following, except
**Core Concept**
Emphysema is a type of chronic obstructive pulmonary disease (COPD) characterized by the destruction of alveolar walls and airspaces, leading to impaired gas exchange and decreased lung function. The physiological effects of emphysema are multifaceted, involving changes in lung mechanics, gas exchange, and overall respiratory function.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiological changes that occur in emphysema. Emphysema leads to a decrease in lung elastic recoil, resulting in air trapping and hyperinflation of the lungs. This, in turn, leads to a decrease in lung volumes, particularly functional residual capacity (FRC), and an increase in residual volume (RV). Additionally, emphysema causes a decrease in the diffusion capacity of the lungs for carbon monoxide (DLCO), impairing gas exchange and leading to chronic hypoxemia. The destruction of alveolar walls also leads to a decrease in the surface area available for gas exchange.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because emphysema is characterized by air trapping and hyperinflation, leading to a decrease in lung volumes, particularly FRC.
* **Option B:** This option is incorrect because emphysema causes a decrease in the diffusion capacity of the lungs for carbon monoxide (DLCO), impairing gas exchange and leading to chronic hypoxemia.
* **Option D:** This option is incorrect because emphysema leads to a decrease in lung elastic recoil, resulting in air trapping and hyperinflation of the lungs.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that emphysema is a preventable disease, and smoking cessation is the most effective way to prevent its progression. The "4 As" of smoking cessation are:
* Ask about smoking status
* Advise smokers to quit
* Assess the smoker's willingness to quit
* Assist the smoker in quitting
**Correct Answer:** B.